Modified Styrene Butadiene Rubber (SBR) polymer/asphalt compositions are known to those skilled in the art. Polymer modified asphalt blends are useful for paving materials, roofing materials, products for protection of car bottoms and other coating applications. Asphalt/polymer blends must have good phase compatibility between the asphalt and the polymer, and must be storage stable at high temperatures for ease of handling and application. Specifically, U.S. Pat. No. 4,333,866 discloses a rubber modified asphalt composition containing styrene butadiene rubber (SBR) and asphalt and a vinyl aromatic monomer such as cinnamic acid. U.S. Pat. No. 5,451,619 discloses an asphalt composition containing styrene butadiene rubber which is epoxidized. Said composition is said to exhibit better compatibility than previous polymer modified compositions. U.S. Pat. No. 5,604,274 discloses a blend of asphalt and epoxyfunctionalized polymer. Styrene/butadiene rubber is not disclosed as part of the composition. U.S. Pat. No. 5,574,095 discloses an asphalt composition containing epoxy or glycidyl functional polymers. Styrene/butadiene is not disclosed as part of the composition. U.S. Pat. No. 5,672,642 discloses a process for preparing asphalt polymer blends comprising contacting sulfur with asphalt and contacting a polymer with the sulfur asphalt mixture. The preferred polymer is a styrene-butadiene-styrene block copolymer. Finally, U.S. Pat. No. 5,331,028 discloses a rubber modified composition containing block styrene butadiene rubber, asphalt and a glycidyl containing ethylene copolymer wherein the glycidyl moiety refers to an epoxide containing functionality.
Surprisingly, Applicants have discovered a method for eliminating or reducing the problem of phase separation of a random vinyl substituted aromatic/C.sub.4 -C.sub.6 conjugated diolefin polymer/asphalt hot mixture during processing and storage.